In the past, trialkyl sulfonium halides have been utilized as methylene transfer agents in conjunction with aldehydes. Hatch in Journal of Organic Chemistry 34 2133 (1969) disclosed that sulfonium halides in sodium hydroxide can be utilized to transfer alkyl and alkenyl groups to activated aldehydes particularly those aldehydes having an .alpha., .beta. -unsaturation. See also U.S. Pat. No. 3,426,046, Feb. 4, 1969. Merz also reported in Angew Chem. 83 No. 19, page 867 (1973), that phase transfer catalysts can be utilized in conjunction with alkylsulfonium iodides as methylene transfer agents for acetophenone giving yields of 36% in 72 hours. In order to increase the yields with methylene transfer agents, Yano et al. disclosed in J.C.S. Chem. Comm., 527 (1973) utilizing long chain alkyl dimethyl sulfonium salts such as lauryl dimethyl sulfonium halides as methylene transfer agents. It was through these long chain alkyl dimethyl sulfonium halides that good yields of the methylene addition product with ketones such as benzyl methyl ketone are obtained.
However, in the past, use of the trimethyl sulfonium halide salts as methylene transfer agents for ketones has not proven to be successful due to the low yields and long reaction times necessary to carry out this reaction. Therefore, the use of these cheap alkyl sulfonium halides as methylene transfer agents has been avoided for other than activated aldehydes.